Production of cathode-forming sheets.



. groove. ln so doing",

e c ya@ @qui ll. ,lammeren e Q Specca tion of Letters Patent.

latenterl lllieca t, MM5.

' l n n siding in the boreugh of canhattain city, county, :r id "ite of lew iforlr, nave in rented neu' and useful linprweinents in the liroflucton of Cathodelfcrming lheets; and l do hereby declare the follow ing' to be e full, clear, and exact description of thc invention, such as `will enable others skilled in the art to winch-'it apperteins to make and use the saine.

VAEhe present invention relates to the elecn trolytic production of cathode starting sheets sind particularly to the cathode blank employed in the production of the starting sheets.

To prepare the cathode blank upon which the cathode starting sheet is to be deposited, it is customary in the art in most cases to r,give the blanken eXtrei/nely thin coating of e suitable grease or the like, that is to say, a coating sui'licieutly thin to permit the pas "age of the depositing current, and yet of a character appropriate to subsequent stripn sing of the deposited starting sheet from the tace of the blank. yiluitablue greases for this purpose are well irno'afvn, Well as their manner of application to the blank and need 'not be further referred. to herein.

ln order to assist in the stripping of the deposited cathode starting sheet from the blank, and particularly to permit the startinf?,n sheet to he detached in such manner as to prescrire its uniformity of outline along its edges, it has been heretofore proposed to provide the cathode blank with u scratch groove. In practice, this groove is made uponr both surfaces of the blank, and at e, short distance from the outer edges thereof. The groove is ricade of a sufficient depth to permit a, skilled operator to detach the cleposited starting sheet along the line of the there is left upon the blanluoutsidc of the scratch-groove, a quantity oi undetached deposited metal, which is subsequently stripped from the blank and which is thereafter reineltcd as scrap'. lt represents an extra expense of considerable amount in large operations, as, for insmi'ice,

in the electfc deposition of metellic cfypper from its solutions.

El.. number of factors contribute to the .amount aud extent of the loss referred to. instance, the stripping of the scrap the c ithode blank, sitter the mais hotly portion of the cathode starting sheet has been detached is an operation which itself involves trie employment of skilled labor, and, in practice, is found to occupy about one-half of the time required for the complete stripping of the plete. Furthermore, it occasionally happens that, in spite of the presence of the scratch-groove, the skilled l.operator is unable to successfullyv detach the deposited starting sheet along the line of the groove, so that, at times, a starting sheet will be broken or ruptured along its edges or otherwise so as to become unutilizable for the purposes for which it is in tended. These and other difficulties are cumulative in actual practice and' represent an important total expense in the general operation. To this should be added the cost ef rcinelting the scrap and the damaged sheets. This rez/melting usually takes place in the reverbcratory furnaces employed for melting the metal from which the anodes to be refined are cest. lt involves the loss of time incident to the collection and transfer of the scrap to the furnaces and the charging of the furnaces therewith and cuts down the capacity of the furnaces for their regular operation. lt has also been heretofore proposed to provide the outer edges of the blank with. a scratch groove similar to that employed in practice upon the surface of the blank. ln actual operation, however, the scratch groove at this location has heretofore been found ineffective as a means for insuring' the stripping of the deposited star*- ing sheet from the blank. The reason for this l believe to be that because of the density of the current along the outer edges of the blank, in the usuel installation, it has been impossible to avoid the bridging over of the metal along. the outer edges of the blank to such a degree as to firmly unite the metal deposited upon one surface of the' ping'ot` the scrap and its subsequent reutilization. Furthermore, it lengthens the durability of the blanks themselves, by reason of the readiness with which they are stripped and the moderate vicissitudes of wear and possibility it' injury during the stripping operation.

In the accompanying drawing, Figure l represents in side elevation and partial section a cathode blank embodying my invention; Fig. 2 represents ay view similar to that oi'; Fig. l, of a modication of the cathode blank; Fig. 3 represents, on an enlarged scale, a cross-sectional view ot a portion of one of the cathode blanks, this view being taken along the side edges of the blank of Fig. l or along the side or Abottom edges of the cathode blank ot' Fig. 2; and Fig. i represents, on an enla Lged scale, a cross-sectional view of portion of the bottom edge of the cathode blank illustratedin Fig. 1.

In order to obtain the cathode starting sheets, I employA a series ot' cathode blanks a of suitable material, such as, for instance, rolled copper, of suitable dimensions, as, for instance, ot a thickness of say oi' an inch and of appropriate height and width (say SXS or xlf). It will, of course, be understood that I do not limit the size of the cathode blank to these particular dimensions, but may alter them to suit particular `and bottom peripheral edges.

conditions of use.

The novel cathode blank of the present invention is provided at or in its peripheral edges with insulation of a suitable nature and thickness to substantially prevent deposition thereon and bridging thereover, dui ing the electro-deposition upon the side sur faces of the cathode blank. This insulation is advantageously ot' an adhering nature, securely held in place at the edge periphery of the blank. In the cathode blank of Fig.

,1, insulation is provided only at the side ledges ot' the blank, while in the cathode blank of Fig. 2,'it is provided at both side In the embodiments oit the invention illustrated, the edges are provided with a recess or depres sion, of such a conguration as to receive and retain a suitable insulating material b, ot' a kind which will adhere firmly to copper, as, for instance, asphaltuin, asphaltum mastic, Chatterton compound, or the like. As illustrated in,Fig. 3, the groove or recess is of an undercut configuration, suoli that the insulation is held securely in place.

In the cathode blank ot Fig. '.l, the bottom edge is provided with a V-shaped groove d, of relatively considerable depth as compared with the thickness of the blank. This groove is illustrated in detail in Fig. 4, as of a depthsubstantially equal to the thickness of the cathode blank, and I prefer to make it of at least this depth in order to realize its best advantages. In Fig. :2, the recess or depression along the bottom edge of the cathode blank is filled with a body of insulating material.

It will be seen that with recesses 01 depressions such as indicated in Fig. 3, which shows one of the lnany forms which can be used, the insulating material will be securely held in place in the edge periphery of the cathode blank.

As a result of the insulation at the edge of the cathode blank, instead of forming a strong cohering deposit over the edges of the cathode and thereby locking to the blank the metal deposited upon the opposite sides thereof so that detachment of the metal without rupturing is prevented or made difficult, such deposition and bridging over the edge of the cathode blank, is substantially prevented. As a result, the deposit upon each side of the cathode blank is found to he more readily detachable, even by unskilled labor. Any such stray deposit as may i'orin at the edge ot the blank is of such a character that it does not materially interfere 4with the clean Aand satisfactory stripping of the deposit from the iiat surfaces of the blank in the form of unruptured cathode sheets.

It will be understood that I do not restrict myself to any particular insulating filling, nor even to a filling of a plastic material, inasmuch as a suitable Wood, hard rubber, bakelite, vulcanite, or like insulating insert may be used to ill or close the recess or depression in the edge of the blank.

The provision of insulation at or in the side edges or both side and bottom edges of the cathode blanks introduces suiiicient resistance locally in the current path to substantially prevent any deposit and consequent bridging across such peripheral edges of the cathode blanks, as has been already ointed out.

'While I have illustrated and described the embodiment of my invention. which I have `found in practice to give particularly good results, it is believed to be broadly new to prevent any substantial bridging across the peripheral edges of the cathode blanks b v the provision, at or in such edges, of an adhering body ot' insulating material securely held in place at the edge periphery, and of a suitable nature and thickness to substantially prevent deposition thereonl and bridging thereover. It is also believed to be broadly new to provide such a cathode blank with insulation secured at or in its side peripheral edges, so arranged as to leave the side surfaces of the blank free and unobstructed, and of a suii'able nature and thickness to prevent deposition thereon and bridging thereover. The appended claims are accordingly intended to have a corre- 4 spondingly broad interpretation.

`What claim is:

' LA' cathode blank for cathode-forming sheets, provided with insulation secured at or in its side peripheral edges, said insulation being of a 'suitable nature and thickness to substantially prevent deposition thereon'and bridgingthereover, and being arranged to-leavetheside surfaces of the y blank reeandunobstrncted, whereby clean stripping of thedeposit from the full side surfaces of th'eblank in the formfof unruptnredcathode sheets can be eiiected; sub-4 i stantially as described. Y

, 2. A' cathode blank for cathode-forming sheetsj provided :with an adhering body of insulating material securely'held in place at or' in theedgej l periphery of theblank, said body of'materialbeing of a suitable-,nature and thickness to siibstantially preventv depo-v sition lthereon 'and bridging thereover;l whereby Aclean stripping of the deposit from the` side surfaces ofthe blank inthe form v`si ofnnruptured cathode sheets can be eectedg' 'being undercut and having a filling of insulating material; substantially as described.

5. A cathode blank for cathode-forming' sheets, provided along its side and bottom edgeperipheries with an undercut groove having a filling of insulating material; substantially vas described.

In testimony whereof l afiiX my signature,

in presence of two Witnesses.

EDMOND A. GUGGENHEM. Witnesses: i

FREDEnroK A. COLLINS, THoMAsE, FELL. 

